Process of making cylindrical rollers



Dec. 9, 1930.

PROCESS MAKING CYLINDRICAL ROLLERS Filed March 5, 1950 iatented Dec. 9, 1.930

Bonn G. NICE, F HAIBORO, EENNSYLVA-NIA PROCESS or MAKING cYLINnRIcAnRoLLEas Application filed March 5,1930. seriar-"Na sa321.

-UNITED STATES o;i=.:i-icEj Hardened steel rollers accurately sized and polished or finished and of cylindrical form are extensively used in roller bearings, but as now manufactured the use of an automatic screw machine is involved and the rollers are expensive and troublesome to make.

It is the principal object of the present invention to provide hardened steel rollers of accurately sized and polished or finished cylindrical form at comparatively little cost, and, according to m invention, this is done by grinding a part 0 'the surface of hardened steel balls between two parallel planes into cylindrical form by passing the balls through ,5 a centerless grinder. The ends of the resulting rollers are of the form of segments of a sphere, but that is immaterial since it is the cylindrical portion of the rollers that does the work required in a roller bearin It is an advantage of the invention that the hardened steel balls, which are ground in a centerless grinder into cylindrical roller form, can be inexpensively produced, because in their production some of the costly steps in the process of making hardened, ground, sized and olished steel balls, such as are used in ball earings, are unnecessary and are omitted.

The invention comprises the improvements 39 herein described and claimed at the end here o a I In the following description reference will be made to the accompanying drawings forming part hereof and in which the single figure is a diagrammatic view illustrative of so much of the process as can be well explained by illustration.

Referring to the drawing, 1 indicates, partly in full and partly in dotted lines, a a hardened steel ball rough ground to size, and 2 indicates a cylindrical roller having ends 3 of the form of segments of a sphere pro' duced by grinding a part of the surface of the ball 1 included between two parallel planes into cylindrical form by passing the ball through a centerless grinder. The use of'an automatic screw machine is eliminated. Theballslmaybemadeby cold heading slugs into generally cylindrical form. This is a process of cold forging and it produces projectingfins a-nd-thelike and also sets up strains in the metal. i'lxhe'spherical forms are normalized by heat treatment, for example, at 600 F. more or less. The normalized spherical bodies are then flashed or snagged to remove the fins. This is done in the well known manner by passing them between appropriately rotated and constructed discs or elements of which one usually has a fiat grind ing face and the other a spiral groove. The spherical bodies are then rough ground to true them up and for size. This is done in a well known rough ball grinder which usually has two opposed g *inding faces suitably revolved.

are hardened by heat treatment. Thereafter the balls are tumbled to take 05 scale. The described steps in the manufacture of the balls ready for centerless grinding are well understood by those skilled in the art, and in all cases all of them are not necessary. The point is that the expensive steps in the process of making standard steel balls, such as are used in ball bearings, are omitted, and those skilled in the art will note that the steps of soft lapping to polish and true up, and of hard lapping to takeoff scale, and of tumbling in leather to burnish are omitted.

A part of the surface of hardened steel balls included between two parallel planes is ground into accurately sized and finished cylindrical form by passing the balls through a centerless grinder, which is a well known commercially available apparatus in which the balls pass axially along cylindrical rotating grinder rolls.

It will be obvious to those skilled in the art to which the invention relates that modifications maybe made in details of procedure without departing from the spirit of the in-' vention which is not limited to such matters or otherwise than the prior art and the appended claims may require.

I claim:

1. The process of making cylindrical rollers having ends of the form of segments of a sphere, which comprises making and hardening steel balls, and grinding a part of the surface of the balls included between i The roughground balls are then tumbled to take off grinding scratches and" 52rd v V i,7e 4,4es

two parallel planes into cylindrical form by passinglthe balls through a centerless grinder. T e rocess of making cylindrical rollers having ends of the form of segments I of a sphere, which comprises converting steel slugs into generally spherical bodies by cold heading them, normalizing the metal of the nerally spherical bodies by heat treating I 7 -t em, removing fins from the normalized spherical bodies by flashing them, truin up i i .and sizing the spherical bodiesto ball orm by rough grinding them, hardening the balls].

V I by heat treating them, and grinding a part i of thesurface of the balls included between two arallel planes into cylindrical form by a passing the balls through a centerless grinder. v BUDD' G. NICE. 

